Slack adjuster



J. W. CLARK SLACK ADJUSTER Get. 24, 193 9.

Original Filed Oct. 11, 1928 v 2 Sheets-Sheet l Oct. 24, 1939. w CLARK 2,177,451

SLACK ADJUSTER Original Filed Oct. 11, 1928 2 Sheets-Sheet 2 A? fillllll l llllll Juno) J M llarl I! I I illt vun Patented Oct. 24, 1939 1 UNITED STATES PATENT OFFICE October 11, 1928. 24, 1938, Serial No. ary 27, 1928 39 Claims.

This invention relates to slack adjusters for use with air brake equipment for railway cars, locomotives, tenders, urban and interurban cars and the like.

It is primarily an object of the invention to provide a slack adjuster which is operable through the instrumentality of the mechanism substantially as hereinafter described, which mechanism becomes active upon abnormal travel of the piston comprised in said equipment.

An important object of the invention is to maintain substantially uniform the travel of the aforesaid piston.

Another important object of the invention is to provide means operating under the influence of the push rod connected to said piston to take up automatically any slack which may occur as a result of wear upon the brake shoes or from any other cause which would effect the desired uniform piston travel.

A further important object of the invention is to provide an automatic slack adjuster, which will effectively perform its intended functions directly and simultaneously with the operation 5 of the brakes, thereby entirely preventing or greatly reducing what is known in the art as undesired action.

The invention consists in the details of construction and in the combination and arrangement of the several parts of my improved slack adjuster whereby other objects and important advantages are attained and the device rendered simpler, less expensive and otherwise more convenient and advantageous for use as will be hereinafter set forth, or will become apparent during the course of the following description.

In order that my invention may be better understood, I will now proceed to describe the same with reference to the accompanying drawings, wherein:

Figure l is a diagrammatic view illustrating a slack adjuster constructed in accordance with an embodiment of my invention;

Figure 2 is a diagrammatic view illustrating a further embodiment of my invention;

Figure 3 is an enlarged detailed View in elevation illustrating the mounting of the capstan and certain of the parts associated therewith; and

Figure 4 is a horizontal sectional view taken substantially on the line 44 of Figure 3.

My improved slack adjuser may be employed in connection with the regular brake equipment without any material change in the rigging thereof.

As particularly illustrated in'Figure 1', C de- This application December 247,683. In Canada Janunotes a brake cylinder in which operates a well known type of piston carrying the push rod l. The rod I is operatively connected through the medium of a pin 2 with the live cylinder 3 which constitutes parts of "all brake equipment.

The pin 2 also provides an operative connection between the rod l and an end portion of the operating lever 4, which constitutes an element of my improved slack adjuster. The rectilinear movement of the push rod I imparts swinging movement to the lever A as well as to the live cylinder lever 3, and for which reason said lever 4 is provided with a slot 5 through which the pin 2 is disposed in order to provide for such swinging movement. The slot 5 permits the lever 4 to move lengthwise at the connection afforded by the pin 2 allowing for a greater distance from the pin of the push rod to the center of the capstan or rotatable member A. The lever 4 has pivotal connection with the upper portion of a pin 6 which is supported by a capstan frame F. This frame F is bolted or otherwise affixed to a bracket B which in turn is bolted or otherwise effectively secured to the car sills.

Rotatably mounted upon the pin 6 is a capstan or rotatable member A provided with an upper flange 9 and a lower flange Ill. The peripheral portion of the upper flange 9 is provided with a series of ratchet teeth ll herein disclosed as fifteen in number and of duplicate form. The lower flange I0 is provided in its peripheral portion with the spaced ratchet teeth l2 and herein disclosed as ninety in number and of duplicate form.

Each of the teeth II is placed in vertical alignment with a point midway between two adjacent teeth l2, or may be placed in vertical alignment with one of the teeth l2.

The lever 4 has pivotally connected therewith, as at M, a dog or pawl I5 which is constantly urged into contact with the flange 9 by means of the spring I6 having one end portion secured, as at H, to, the lever 4. Pivotally connected, as at [8, with the capstan frame F is a second pawl 19 which is constantly urged into contact with the flange ID by means of the spring 20, also carried by the capstan frame F.

Winding on the capstan or rotatable member A between its flanges 9 and Ill is a cable or chain 2 one end ofwhich is operatively connected, 50 as at 22,.with the free end of a lever 23. The opposite end of the chain or cable 2| is suitably anchored, as at 24, to the capstan or rotatable member A so that upon rotation of said capstan under the influence of the pawl 15, a pull will 55 be exerted upon the outer or free end portion of the lever 23, or, in other words, the free end portion of the lever 23 will be moved toward the capstan.

The lever 23 is supported substantially midway its ends, as at 25, between the bars of the guide 26 and said lever 23, at 21, is operatively connected with the connecting rods 28 which in turn are also operatively connected, as at 29, with the dead cylinder lever 30. It is to be noted that'an extended end portion of the dead cylinder lever 38 has movement between the upper and lower bars of the guide 26 and is prevented from length wise movement by the pin 3] moving in the slot pr vid in the guide bars 26'. it isalso to be noted that the fulcrum point 29 of the dead cylinder lever 30 is disposed upon the center line of the brake cylinder C.

The end portions of the bars of the guide-'26 adjacent to the cylinder C are bolted, as at 33, to the cross bar 3 3 and the oppositeend portions of the bars of the guide 26 are adapted to be bolted or otherwise suitably secured to a car sill. It is also to be noted that one end portion of the cross bar 35 of which the guide bars 26 are aifixed is bolted, as at 35, to a cylinder bracket 36, while the opposite end portion of said cross bar 34 is bolted to a car sill or,'ii desired to an extended end portion of the capstan bracket B.

Connected with the lever 23 and with a suitably positioned bracket 31 is a retractile spring 38 of requisite tension to keep the dead cylinder lever 30 in its proper place and thus permit the brakes to be released. The dead cylinder lever 30 is operatively connected with" the live cylinder lever 3 at points midway the ends of said levers by the tie rod 39. 7

As the rod I moves outwardly, swinging movement is imparted to the lever 4 and in the event that the outward movement of the rod I, or piston travel, is for a distance greater than that for which the capstan A is set without operating, the pawl it engages the first tooth H on flange 9 and in the course of its movement will cause the capstanor rotatable member A to be rotated a distance sufficient to permit the pawl l9 toengage'the next tooth l2 on the lower flange l0 and to hold the capstan against retrograde rotation. When the brakes are released and the operating lever 4 moves backwards, the pawl [5 will engage the tooth H immediately succeeding the tooth with which it previously co-operated and when the brakes are again applied and the rod I moves outwardly, the capstan or member A will be rotated a distance sufiicient to bring the pawl l9 into cooperation with three of the teeth [2 on the lower flange l0 within the space separating the perpendicular alignments of the two teeth H on the operating or upper flange 9 between which the pawl l9 was brought into action in making such operation. The capstan or member A is held against retrograde movement by the pawl l9 which, as particularly illustrated in Figure 4, has its working and engageable with three of the teeth I2, I 7

During this rotation of the capstan ormember A just referred to, a pull will be exerted upon the chain or cable 2| resulting in moving the adjacent end portion of the dead cylinder lever 30 in a direction away from the cylinder C, and which movement in proper ratio is transmitted to the live cylinder lever 31 By this means the slack is taken out of the brake rigging and it wm be noted that the desired uniform travelfof the brake piston, or more particularly its rod 1, will be maintained.

Under normal conditions, or when the brake piston has the desired travel or less, it will be understood that the swinging movement of the operating lever 4 will have. no effect upon the movement of the capstan A, as the pawl IE only moves forward and backward in the space separating the two teeth II on the flange i between which the pawl I5 is moving. Upon further wear of thebrake shoes, brake rigging and wheels, the pawl l9, due to the influence of the pawl l5 acting upon a tooth ll of the operating flange 9, coacting with the teeth l2 of the holding flange ID will engage the succeeding, intervening teeth between the alignments hereinbefore referred to until the pawl [9 has engaged three teeth ii, the

central one of which is either in perpendicular alignment or adjacent to a point that is in perpendicular alignment with the last succeeding tooth l l of the alignments hereinbefore referred to on the operating flange 9, then the slack adjuster upon additional wear of the parts above named will again operate as previously described and each succeeding operation takes place in like manner.

For the purpose of explanation, a plurality of teeth 12 are to be considered in sections defined by the perpendicular alignments of the teeth ll.

When the pawl I5 has engaged a succeeding tooth H and has operated the adjuster, the pawl l9 will engage teeth i2 of the following section, but the rotating member will not be rotated a distance sufficient to permit the pawl it to engage teeth I2 corresponding in position to the teeth of the section with which it formerly cooperated. This is due to the fact that the operation of the adjuster shortens the piston travel while said operation is being made. Again when the adjuster has taken up the slack as hereinbefore described 0 so that the central tooth of the pawl l9 has engaged tooth 52 either in perpendicular alignment or adjacent to a point that is in perpendicular alignment with a tooth H, the central tooth of the pawl it must engage a tooth l2 beyond the alignment just mentioned before the pawl l5 will engage the succeeding tooth I l to again operate the adjuster. Because of the two foregoing reasons it is seen that the adjuster successively takes up slack by the pawl l9 engaging in succession several of the teeth l2 between the actions" of the pawl l5 engaging successively two teeth H. Also, it is seen that the slack taken up by the major operation due to the pawl I5 engaging a tooth H is made less by the successive action of the pawl l9 engaging the teeth [2.

In the embodiment ofmy invention as illustrated in Figure 2, the cable or flexible member 2| coacts with the capstan A in the same manner as referred to with respect to the cable 2|,

that is to say, resulting in a pull being exerted thereon as a' result of abnormal travel of the push rod i. This member M is operatively engaged, as at MI, with the connecting rod ll which in turn is operatively connected, as at '32, with an end portion of a lever 43.

Operatively connected with the lever 43 at a desired point intermediate its ends is a rod 44, which in turn is operatively connected as at 51 with a dead lever 15. The end portion of the lever 43 remote from the connecting ro-d' ll is operatively connected as at 55 through the medium of a tie rod 46 with a second lever ll as at 56 herein disclosed as in converging relation with res ectto the ever 4's; This lever 41 has its end portion remote from the tie rod 46 operatively connected as at 54with a rod 48, which-issuitably connected with abracket 49 adapted "to be secured to a car sill. The lever 41 is operatively connected through the medium'of atie'rod 50 with the live cylinder 1ever-3.

Upon rotation of the capstan A', a pull exerted upon thecable or member 2| results in a pull being imposed upon the rods and 50 one toward the other. This action' results inslack being taken out of the brake rigging; and thereby a substantially uniform" brake piston travel is maintained. Connected with the lever 43 and with a suitably positionedbracket 5| is a retractile spring 52 of requisite tension, serving to maintain the levers 43 and -4 1 in their proper place and to overcome the inertia of said levers While the brakes are beingreleased. Coacting with the opposite end portions ofthe levers 43 and 4'! are the lever carriers 53 of a conventional type. The embodiment of the invention shown in FigureZ tends to adjust the slack in the brake rigging in substantially the same manner as has been set forth in connection with the embodiment of the invention illustrated in Figure ll Hereinbefore the direct and simultaneous operation of the slack adjuster with the brake application has been described; but by turning the capstan upside down, changing the rackbar so that it comes into contact with the opposite side of the pinion from which side said bar is shown as contacting in the accompanying drawings, and changing the position of the pawls so that they engage their respective teeth in the proper manner, the slack adjuster can be caused to operate while the brakes are being' released. Herewith arises the question of what is known as undesired action, thati's the operation of the slack adjuster upon the tiltingof the truck levers caused by track conditions, the movements of the trucks and certain parts of the running gear. The operation of the slack adjuster due to such causes as listed above results in 'a brake piston travel much shorter than what is desired; This condition exists to a greater extent upon freight than passenger cars, due to the looser construction of the former. Yet, frequently the last named cars obtain too short a piston travel due to the aforesaid undesired actionof-an automatic slack adjuster resulting in damage therefrom.

The direct and simultaneous operation of the slack adjuster with the brake application as fully described he'reinbefore and as disclosed in the accompanying drawings acts as a causative agent to prevent the above described undesired action. It'is seen that when the brakes are applied,the piston'moves forward, and if the pistons movement is abnormal as described, hereinbefore the pawl l5 comes into contact with a tooth II, and no slight tilting of the truck levers, nor movements of parts of the running gear, nor trucks, can cause the aforesaid undesired action of the slack adjuster. This fact is apparent when it is understood that during such operation of both the'brakes and the slack adjuster simultaneously "the inertia of both the brake rigging and the slack adjuster is to be overcome, and the adjustment of parts of the rigging'is to'be 'accomplished, and the travel of the-brake piston shortened synchronously with said simultaneous operations. With such aflmethod of operation as immediately before described the slack adjuster will not operate until a positive, although slightly longer piston travel is obtained. R is 3 submitted that the slack adjusting mechanism hereinbefore described, particularly the struc ture of the holding flange possessing teeth entirelyaround said flange, disclosed as being relatively small inrespect to the operating teeth, and

arranged in succession one immediately adjacent to the other, is well adapted for the successful and practical operation of the slack adjuster simultaneously with the brake application.

Whereas if the operation of the slack adjuster were changed so that it operated as the brakes are being released, which method of operation is universally accepted as being the best, the causes being absent which prevent the aforesaid undesiredaction inthe first explained method of operation, each slight tilting of the truck levers, or movement of the trucks or parts of the running gear toward the center of the car would cause the piston to move forward unduly carrying with it the piston rod, the operating arm, and the pawl thereon. These movements would permit said pawl to become engaged with the operating teeth so frequently that a too short a piston travel would result therefrom, resulting in the brake shoes not being removed from the wheels upon release of the brakes, giving too strong a braking power, and thereby causing slid flat wheelsand broken equipment.

It is to be understood that the capstan A is to beset with respect to the center of travel of the pin'2 in accordance with the required uniform travel of the brake piston. Freight cars generally are supposed to have an eight inch running piston travel, passenger cars seven inch running travel, tenders six inch running travel, and locomotives'four inch running travel. To compute the correct distance for the required piston travel, an isosceles triangle is constructed, the vertex of which is the'center of pin 6 and the side lines are drawn through two adjacent teeth H on the operating flange 9. Add to the above triangle a triangle formed by drawing a line from the center of pin 6 through a point on the periphery of the holding flange [0 in perpendicular alignment with a tooth H .on the operating flange 9. The other side of this triangle is a line drawn from the center of pin 6 through the next tooth [2 on the holding flange l0. Bisect the sum of these triangles; find the point at which the outer sides of the triangle, formed by the sum of the above specified angles, are eight inches apart on a line perpendicular to the bisecting line. The distance from the center of pin 6 to the point where the line drawn between the outer sides of the sum of the above specified triangles intersects the line which bisects the sum of the two angles is the correct distance to set the center of capstan A from the center of travel of pin 2 for an eight inch piston travel. In like manner the correct setting for seven, six and four inch piston travel can be computed.

No definite diameter is required for the flanges 9 and I0, although in practice from eight to twelve inches appear to be convenient sizes. The aforesaid flanges may be transposed to suit the convenience of installation.

It is to be understood that the number of teeth I I and also the number of teeth l2 may be varied so long as each set of teeth has a definite relation with respect to the other set of teeth.

From the foregoing description it is thought to be obvious that a slack adjuster constructed in accordance with my invention is particularly well adapted for use by reason of the convenience and facility-with which it'may be assembled, installed and operated manually when suchoperationis required; and it also will be obvious thatmy invention is susceptible to some changes and modifications in both structure and operation, such as effecting the operation of the same upon release of the brakes, without departing from theprinciples and spirit thereof andfor these reasons I do not wish to be understood as. limiting myself to the precise arrangements and formations of the several parts herein shown and described in carrying out my invention in practice except as hereinafter claimed. I I

This application is. acontinuation of application Serial No. 311,909, filed October 11, 1928, and renewed April 11, 1935. Reference is also made to application Serial No. 207 ,858, filed May 13, 1938, which discloses and claims a specific embodiment of the invention covered by the broad claims of this application. I

1. In an air brake equipment, the combination with a push rod and a live cylinder lever operatively connected therewith, a mechanism, means for imposing movement upon said mechanism upon abnormal travel ofsaid push rod, a second lever, said second lever being interposed in the brake rigging, means for holding said'second lever for swinging movement, means for imposing the movement of said mechanism upon said second lever, a thirdlever, said third lever being interposed in the brake rigging, said third lever being supported at one end portion for swinging movement,means for operativelyconnecting the opposite end portion of the third lever to the second lever, an operative connection between the third lever and the live cylinder lever, the aforesaid movement imposed by said mechanism upon said second lever effecting movementof the third lever and the live cylinder lever to take up slack in the brake rigging, and means coacting with the second lever to maintain the second and third levers in proper positions and to overcome the inertia of said levers while the brakes are being released.

2. In an air brake equipment, the combination with a push rod and "a live cylinder'lever operatively connected therewith, a mechanism, means for imposing movement upon said mechanism upon abnormal travel of said push rod, a second lever, said second lever being interposed in the brake rigging, the pivotal mounting for said second lever being intermediate the'ends thereof,

means for holding said second lever for swinging movement, means for imposing the movement of said mechanism upon said second lever, a third lever, said third lever being interposed in the brake rigging, said third lever being supported at one end portion for swinging move'menhmeans for operatively connecting the opposite end portion of the third lever to the second lever, the pivotal mounting for said third lever being at the end portion thereof remote from the operative connection between the aforesaid second and third levers, an operative connection between the third lever and the said live cylinder lever, the aforesaid movement imposed by said mechanism upon said second lever effecting the movement of v the third lever and the live cylinder lever to take up slack in the brake rigging. I

3. The combination with a push rod, a dead lever of an air brake equipment, and a swinging lever operatively engaged with the rod; of means for operatively connectingsaid swinging lever to the dead lever including a rotatabl'emember pot on on fi f e u me ns ,s pQr ed independently thereof, a flexible member windingupon the rotatable member when rotated in onedirection and exerting a pull upon the flexible member, a third lever, a guide for the dead cylinder lever, positioned to contain the fulcrum point for the third lever and to permit the operative connection between the dead cylinder lever and said third leverto be disposed upon the center line of the brake cylinder, means carried by the swinging lever operating upon undue travel of the push rod and swinging lever for imparting rotation to said rotatable member, and means .for holding the rotatable member against retrograde rotation,; normal movement of the push rod operating the swinging lever independently of the rotatable member.

4. A slack adjuster for a brake mechanism comprising a rotatable member provided with a plurality of circ'umferentially arranged elongated ratchet teeth, a dead lever comprised in the brake rigging, an operative connection between said lever and the rotatablemembensaid connection including a transmission lever, a brake cylinder, a guide for the dead lever positioned and adapted to contain the pivot for the transmission lever and to retain the operative connection between the deadlever and the transmission lever substantially upon the center line of the brake cylinder, a cross bar combined with the aforesaid guide,'the transmission lever, the dead lever and the brake cylinder whereby the forces exerted uponthe opposite ends of said brake cylinder are substantially counterbalanced, a push rod of, the brake equipment, an operating arm connecting said rod with the rotatable member, the pivotal mounting for said arm being in axial alignment with the rotatable member, a pawl carried by the arm and engageable with the ratchet teeth, said pawl normally coacting with asingle tooth but engagingan adjacent tooth upon abnormal functioning of the aforesaid rod,

said-rotatable member having a second series of teeth extending therearound, and a pawl engaging said second teeth for holding the rotatable member against retrograde movement, the ratchet teeth of the first series being positioned substantially in vertical alignment with points definiely located and equi-distantly spaced amidst the ratchet teeth of the second series,

5. In an air brake equipment, the combinatio with a push rod and a live cylinder lever operatively connected therewith, a rotatable mechanism, anoperating arm engagedwith said push rod and rotatable mechanism, means carried by said operating arm to rotate the mechanism in one direction, means for preventing retrograde movement of said mechanism, a second lever operatively connected with said rotatable mechanism through the medium of a flexible member, means for-holding the secon-d lever for swinging movement, the aforesaid rotatable mechanism, operating arm, and flexible member being adaptedto exert a pull upon said second lever upon abnormal travel of the push rod, a third lever supported at one end portion for swinging movement, means for operatively connecting the opposite end portion of the third lever and the second lever, an operative connection between the third lever and the live cylinder lever, a dead lever, an, operative connection'between the dead lever and the second lever, the movement imposed upon the second lever upon abnormal travel of thepush rod effecting movement of the third lever, the dead lever, and the live cylinder lever to take up slack in the brake-rigging.

6. In an air brake equipment, the combination with a push rod and a live cylinder lever operatively connected therewith, a rotatable mechanism, an operating arm engaged with said push rod and the rotatable mechanism, means carried by said operating arm to rotate the mechanism in one direction, means for preventing retrograde movement of said mechanism, a second lever operatively connected with said rotatable mechanism through the medium of a flexible member, means'for holding the second lever for swinging movement, theyaforesaid rotatable mechanism, operating arm, and flexible member being adapted to exert a pull upon said second lever upon abnormal travel of the push rod, a third lever supported at oneend portion for swinging movement, means for operatively connecting the opposite end portion of the third lever and the second lever, an operative connection between the third lever and the live cylinder lever, a dead lever, an operative connection between the dead lever and the second lever, movement imposed upon the second lever upon abnormal travel of the push rod elfecting movement of the third lever, the dead lever, and the live cylinder lever to take up slack in the brake rigging, and means coacting with the second lever to maintain the second and third levers in proper positions and to overcome the inertia of said levers while the brakes are being released.

7. In an air brake equipment, the combination with a push rod and a live cylinder lever operatively connected therewith, a rotatable mechanism, an operating arm engaged with said push rod'and the rotatable mechanism, means carried by said operating arm to rotate the mechanism in one direction, means for preventing retrograde movement of said mechanism, a second lever operatively connected with said rotatable mechanism through the medium of a flexible member, means for holding the second lever for swinging movement, the aforesaid rotatable mechanism, operating arm, and flexible member being adapted to exert a pull upon said second lever upon abnormal travel of the push rod, a third lever supported at one end portion for swinging movement, means for operatively connecting the opposite end portion of the third lever and the second lever, an operative connection between the third lever and the live cylinder lever, a dead lever, an operative connection between the dead leverand the second lever, movement imposed upon the second lever upon abnormal travel of the push rod efiecting movement of the third lever, the dead lever, and the live cylinder lever to take up slack in the brake rigging, and a spring connected to said second lever and of a tension to maintain the second and third levers in proper positions and to overcome the inertia of said levers while the brakes are being released.

8. In anair brake equipment, the combination with a push rod and a live cylinder lever operatively connected therewith, a rotatable mechanism, an operating arm engaged with said push rod and the rotatable mechanism, means carried by said arm to rotate the mechanism in one direction, means for preventing retrograde movement of said mechanism, a second lever operatively connected with said rotatable mechanism through the medium of a flexible member, means for holding the second lever for swinging movement, the aforesaid rotatable mechanism, operating arm, and flexible member being adapted to exert a pull upon saidsecond lever upon abnormal travel of the push rod, 2. third lever supported at one end portion for swinging movement, means for operatively connecting the opposite end portion of the third lever and the second lever, an operative connection between the third lever and the live cylinder lever, a dead lever, an operative connection between the dead lever and the second lever, movement imposed upon the second lever upon abnormal travel of the push rod efiecting movement of the third lever, the dead lever, and the live cylinder lever to take up slack in the brake rigging, the pivotal mounting for the second lever being intermediate the ends thereof, the abnormal travel of the push rod exerting a pull on one end of the second lever.

9. In an air brake equipment, the combination with a push rod and a live cylinder lever operatively connected therewith, a rotatable mechanism, an operating arm engaged with said push rod and the rotatable mechanism, means carried by said operating arm to rotate the mechanism in one direction, means for preventing retrograde movement of said mechanism, a second lever operatively connected with said rotatable mechanism through the medium of a flexible member, means for holding the second lever for swinging movement, the aforesaid rotatable mechanism, operating arm, and flexible member being adapted for exerting apull on said second lever upon abnormal travel of the push rod, a third lever supported at one end portion for swinging movement, means for operatively connecting the opposite end portion of the third lever and the sec-- ond lever, an operative connection between the third lever and the live cylinder lever; a dead lever, an operative connection between the dead lever and the second lever, movement imposed upon the second lever upon abnormal travel of the push rod effecting movement of the third lever, the dead lever, and the live cylinder lever to take up slack in the brake rigging, the pivotal mounting for the second lever being intermediate the ends thereof, the abnormal travel of the push rod exerting a pull on one end of the second lever, the pivotal mounting for the third lever being at the end portion thereof remote from the operative connection between the second and third levers.

10. In combination with a dead cylinder lever and an operating member of an air brake equipment,,a swinging lever having one end portion operatively engaged with said operating member and the other end thereof operatively engaged with a rotatable member, means for operating said swinging lever upon oscillation of the operating member of the equipment, means for operatively connecting the rotatable member with the dead cylinder lever through the medium of a flexible member and a third lever, a guide for the dead cylinder lever positioned to contain the fulcrum point for the third lever and to permit the operative connection between the dead cylinder lever and said third lever to be disposed upon the center line of the brake cylinder, normal movement of said operating member operating the swinging lever independently of the rotatable member, means operating upon undue travel of the operating member and swinging lever for imparting rotation to the rotatable member to move the third lever towards the said rotatable member and to take up slack in the brake rigging, and means for holding the rotatable member against retrograde movement.

11. A slack adjuster for a brake mechanism comprising a rotatable member provided with a plurality of circumferentially arranged elongated ratchet teeth, a dead lever comprised in the brake rigging; an" operative connection between said leverand the rotatable member, saidconnection including a transmission lever, a brake cylinder, a guide for the dead lever positioned and adapted to contain the pivotv for thetransmission lever and to retain the operative connection between the dead lever and the transmission lever substantially upon the center line of the brake cylinder, a cross bar combined with the aforesaid guide, the transmission lever, thetdead lever and the brake cylinder whereby the forces exerted upon the opposite ends of said brake cylinder are substantially counterbalanced, a push rod of the brake'equipment, an operating arm. connecting said push rod with the rotatable member, the

pivotal mounting for said arm being in axial alignment 'with the rotatable member, a pawl carried by the arm and engageable with the ratchet teeth, saidpawl normally coacting with a single tooth'but engaging an'adjacenttooth upon abnormal functioning of the push rod, said rotatable member having a second series of circumferentially arrangedteeth; and a pawl engaging said teeth for holding the "rotatable member against retrograde movement, a frame for rotatablysupporting the rotatable member, the aforesaid arm-being supported by said frame, and the second'named'pawl being'pivotally mounted upon the frame.

12. In an air: brake equipment, the combination with a'push'rod and a live cylinder lever operatively connected therewith, an operating mechanism, means'for imposing movement upon, said mechanism upon abnormal travel of said push rod, a second lever saidsecond lever being interposed'in' the brake-rigging and operatively connected thereto, means for holding said second lever for swinging movement, means for imposing the movement of said mechanism upon said second lever, a third lever, said third lever being interposed in the brake rigging and supported at one end portion for swinging movement, means for operatively connecting the opposite end portion of the third lever to the second lever, an

operative connection between the third lever and the live'cylinder lever, the aforesaid movement imposed by said mechanism upon the second lever effecting the movement of the third lever and-the live cylinder lever to take up slack in the brake rigging andto maintaina substantially uniform brake piston travel, and means coacting with the second lever to maintain the second and third levers in proper positions and to overcome the inertia of said levers while the brakes are being released.

13; In an air brake equipment, the combination with a push rod and a live cylinder lever operatively connected therewith, an operating mechanism, means for imposing movement upon said mechanism upon abnormal travel of said push rod; a second lever, said second lever being interposed in the brake rigging and operatively connected therewith, saidsecond lever being adapted to operate asof both the first and the second class, means for holdingthe second lever for swinging movement, means for imposing the movement of said mechanism upon said second lever, a third lever, said third lever being interposed in the brake rigging and supported at one end portion for swinging movement, means for operatively connecting the opposite end portion of the. third lever to the second lever, an operative connection between the third lever and the said live cylinder lever, the aforesaid movement imposed by said mechanism upon said second lever effecting movement of they third lever and the live cylinder lever'to take up slack in the for swinging movement,means for operatively con-.

necting the opposite end portion of thethird lever to an end portion of the second lever, an operative connection between the third lever and the live cylinder lever, said means for imposing pull upon said second lever upon abnormal travel of the push rod effecting movement of the third lever and the live cylinder lever to take up slack in the brake rigging andto maintain a substantially uniform brake piston travel.

15. In an air brake equipment, the combination with apush rod and a live cylinder lever operatively connected therewith, a rotatable member, an operating arm connecting the push rod with said member, means carried by said arm to rotate the aforesaid member in one direction, means for preventing retrograde movement of the said member, a second lever operatively connected with the aforesaid member through the medium of a flexible element, means for holding the second lever for swinging movement, the aforesaid rotatable member, operating arm and flexible element being adapted to exert a pull upon said second lever upon abnormal travel of the push rod, a third lever supported at one end portion ,for swinging movement, an operative connection between the third lever and the second lever. at an adjacent end portion of each, a dead lever, an operative connection between the dead lever and the second lever, the aforesaid movement imposed upon the second lever upon abnormal travel of the push rod effecting movement of the third lever, the dead lever, and live cylinder lever to take up slack inthe brake riggto rotate the aforesaid member in one direction,

means for preventing retrograde movement of the said member, a second lever operatively connected with aforesaid member through the medium of a flexible element, said second lever being adapted to operate as of both the first and the second class means for holding the second lever for swinging movement, the aforesaid rotatable member, operating arm and flexible element being adapted to exert a pull upon said second lever upon abnormal travel of the push rod, a third lever supported at one end portion for swinging movement, said third lever being adapted to operate as of the second-class, an operative connection between the third lever and the second lever, an operative connection between ment imposed upon, the secondv lever upon ab normal travel of the'push rod eflecting movement of the third lever, the dead lever, and the live .Icylinder lever to takeup slack in the brake rig ing.

ano'pe'rating arm-i connecting the push rod with said member, means carried by said arm to rotate the-aforesaid'member in onedirection, means for preventing retrograde movement of the said member, a second'lever operatively connected withaforesaid memberthrough the medium of a flexible element, saidsecond lever being adapted to operateasu'of both the first and the second class, means for holdingthe second lever for swinging movement, the aforesaid rotatable member, operating arm and flexible element being adapted for exerting a pull upon said second lever upon abnormal travel-of the push rod, a dead leven' an'operative connection between the dead lever and the'said second lever, an operative connectionbetween the second lever and the said live cylin'der'lever, the aforesaid movement imposed upon the second lever uponabnormal travel of the push rod effecting movement of the second lever and the live cylinder lever to take up slack in the" brake rigging, and to maintain a substantiallyuniform brake piston travel.

18. In anair'brake' equipment; the combination with a push rod and a live cylinder lever operatively connected therewith, a rotatablememher, "an operating arm connecting the push rod with said member,--'means carried by said arm to rotate theaforesaid member in onedirection, means for preventing'retrogrademovement of the said member, a second lever operatively connected with the aforesaid member through the medium of a flexible element, saidsecond lever being adapted to operate as offboth the first and the second class, means for holding the second lever for swinging movement, the aforesaid rotatable membe Operating arm and flexible elementbeing adapted to exert a pull on said second lever ,upon abnormal travel of the push rod, a brake rigging provided with an operative connection with the second lever ata point intermediate the ends of said second lever, an operative connection between the second lever; and the live cylinder lever, the aforesaid movement imposed upon "the second lever upon abnormal travel of the push rod effecting movement'of the second lever 'and the live cylinder lever to take up slack in the brak rigging, and to maintain a substantially uniform brake piston travel;

19; In combination with the elements of a brake rigging and a' push rod, a slack adjuster for said; brake rigging, said slack adjuster ineluding levers interposed in the central portion of the brake rigging and forming part of the means through whichthe braking force is applied by said push rod to the'brake shoes, an operative connection between said levers, a mechanism operative-ly connected to said pushrod, an operative connection between said levers and said mechanism; means operating upon abnormal travel of said push rodeffecting the movement of said mechanism, said levers being'adapted to transmit the movement of said mechanisrn whereby slack is taken out of said rigging with substantially equal effectiveness in both end portions thereof, and a substantially uniform brake pistontravel is maintained.

20. Inc'ombination witha push rod, a live cylinder lever ,operativelyconnected thereto, a sec class, a'mechanism positioned to one side of the push rod and operatively connected thereto, an

operative connection between the second lever and said mechanism, a dead lever, an operative connection between said dead lever and the aforesaid second lever, an operative connection between the said second lever and the aforesaid live cylinder lever, means operating upon abnormal travel of said push rod for operating said mechanism, the aforesaid second lever being adapted to transmit the operations of said mechanism with substantially equal effectiveness to both the live cylinder lever and the dead lever whereby slack is taken out of the brake rigging, and a substantially uniform brake piston travel is maintained.

21. The combination with a push rod, a live cylinder lever and a dead lever, a swinging lever operatively connected with the rod, means for operatively connecting said swinging lever with the dead lever, said means including a rotatable member positioned to one side of the push rod andsupported independently thereof, a flexible member winding upon the rotatable member when rotated in one direction and exerting a pull upon the flexible member, a fourth lever operatively connecting the flexible member with the dead lever, a guide for the dead cylinder lever positioned to contain the fulcrum point for the fourth lever and'to permit the operative connectionbetween the deadicylinder lever and the fourth leveri'tobe disposed upon the center line of the brake cylinder, means carried by the swinging lever operating upon undue travel of said push rod and swinging lever for imparting rotation to said rotatable member, and means for holding the rotatable member against retrograde rotation, normal-movement of the push rod operating the swinging lever'independently of the rotating member. i

22. A slack adjuster for a brake mechanism comprising a rotatable member provided with a plurality of circ'umferentially disposed elongated ratchet teeth, a dead lever constituting an element of the brake rigging, an operative connection between said leverand' said rotatable member, said connection including a transmission lever and a link connecting said transmission lever with said dead lever, a brake cylinder, a guide for said dead lever positioned and adapted to contain the pivot for the transmission lever, said link-being positioned substantially upon the center line of the brake cylinder, the aforesaid guide, transmission lever, link, dead lever and brake cylinder being combined and adapted to counterbalance the forces exerted upon the opposit'e endsof said brake cylinder, a push rod ofthe brake equipment, an operating arm connecting said pushrodi with said rotatable member, a pawl carried by {the arm and engageable with the ratchet teeth, said pawl normally coacting with a single toothbut engaging an adjacent tooth upon abnormal functioning of the push rod, said rotatable member having a second series of circumferentially disposed teeth, and a pawl engaging said second series of teeth for holding the rotatable member from retrograde movement, the teeth of the first series being positioned in vertical alignment with-points definitely located and equidistantly spaced amidst the teeth of the second series,

23. In combination with:a dead lever, a live cylinder lever, a push rod of a brake equipment, a rotatabl member, a swinging lever having one end portion operatively connected to said push rod and the other end thereof operatively con- .nected to the rotatable member, means to operate said swinging lever upon oscillation of said push rod, means for operatively connecting the rotatable member with said dead lever and said live cylinder lever, said means including a fourth lever, said fourth lever being adapted totransmit the movements of the rotatable member with substantially equal effectiveness to both said dead lever and said live cylinder lever, normal movement of said pushrod operating theswinging lever independently of the rotatable member,

means carried by saidswinging lever to impart rotation to the rotatable member to move the fourth lever toward the said rotatable member upon abnormal travel of said push rod and said swinging lever, means for holding the rotatable member against retrograde movement, the last named means coacting with aforesaid means carried. by said swinging lever whereby slack issuccessively taken out of the brake rigging.

24. A slack adjuster for a brake mechanism comprising a rotatable member provided with a plurality of circumferentiallyarranged elongated ratchet teeth, a dead lever, an operative conneciion between said lever and said rotatable mem- :ber, said connection including a transmission lever, a brake cylinder, a guide combined with said dead lever and said transmission lever whereby the forces exerted upon the opposite ends of said brake cylinder are substantially counterbalanced, a push rod-of the brake equipment, a pawl engageable with saidratchet teeth,

said pawl normally coacting with a single tooth,

but engaging an adjacent tooth upon abnormal functioning of said push rod, said rotatable mem 1 ber having a second series of circumferentially arranged teeth, a pawl engaging said second series of teeth forholding the rotatable member against retrograde movement, the said second pawl and the second series of teeth being adapted to cooperate with the first named pawl and the first named series of teeth whereby slack is succes'sively taken out of said rigging, a frame for rotatably supporting saidrotatable member, an arm supported by said frame for swinging movement, the first named pawl being carried by said swinging arm, said arm operatively connecting the push rod with said rotatable member, the second named pawl being pivotally mounted upon the frame.

25. The combination with a push rod of a brake equipment, a dead lever thereof, a rotatable 'member, a transmission lever, a swinging lever, one end of said swinging lever being operatively connected with said push rod and the other end portion thereof being operatively connected with said rotatable member, a flexible element winding on said rotatable member and operatively connected to said transmission lever, said transmission lever being operatively connected to aforesaid dead lever, a-guide adapted to serve as a brace for the brake cylinder, as a guide for the dead lever, a pivot for the transmission lever,

and to retain the operative connection between 2; revg re 1:

trod, an operative connection between said swin ing lever and'saiddead cylinder lever, said connection-including' a rotatable member, a transmission lever" and aflexible element to wind on saidrotatable memben'said'swinging lever having'swinging movement with respect tothe axial center of the rotatable member, a guide for the dead cylinder lever, said guide being adapted to serve asra brace for the brake cylinder, a pivot for the transmission lever, and to retain the operative connection between the aforesaid transmissonlever and said dead cylinder lever substantiallyupon the center line of the brake cylinder, the normal travel of said push rod operate ingrt'he swinging lever independently of the rotatable member; means forimp-arting rotation to said rotatable member uponunduetravel of said push rod to take up successivelyslack in the brake rigging, and means for holding therotatable member against retrograde movement.

27. A mechanismto control the travel of the piston contained in an airbrake cylinder, comprising a rotatable member provided with a plurality of circumferentially arranged elongated ratchet teeth, a member comprised in the brake rigging, an operative connection between said member and the rotatable member, a push rod of the brake equipment, an operating ar-m connecting said push rod with the rotatable member, a pawl carried by the arm and engageable with the ratchet teeth, said pawl normally 'coacting with a single tooth but engaging an adjacent tooth upon abnormal functioning of the push rod, said rotatable member having a second series of relatively small teeth extending therearound and'arranged in succession one 1m.- mediately adjacent to the other, said teeth being equidistantly spaced and with a plurality, of said teeth within the 1 perpendicular alignments of thefirst named teeth, a pawl engaging said second series of teeth for'holding the rotatable member against retrograde movement, said sec: ond pawl and said second series of teeth being adapted to -cooperate with said first pawl and of the piston by the distance said rotatable member is set from thepush rod. 7

2 8. A mechanism to control the travel of the piston contained in an air brake cylinder, comprising a rotatable member provided with a plurality of circumferentially arranged elongated ratchet teeth, a member comprised in the brake rigging and op-eratively connected with the rotatable member, a push rodof the brake equipment, an operating arm connecting said push rod with the rotatable member, a pawl carried by the arm and engageable with the ratchet teeth, said pawl normally coacting with a single tooth but engaging-an adjacent tooth upon abnormal functioning of the push rod, said rotating member having a second series of teeth extending therearcund and arranged in succession one immediately adjacent .to the other, said second series of teeth consisting of a multiple of said first series of teeth, a pawl engaging said second series of teeth for holding the rotatable member against retrograde movement, said second pawl and said second series of teeth being adapted to cooperate with said first named pawl and said first series of teeth whereby the said second pawl'successively engages several of the teeth of the said second series between the actions of said first named pawl engaging successively two adjacent teeth of said first series, and with a definite number of teeth in each of the aforesaid series, said mechanism being adapted to determine the travel of the piston by the distance said rotatable member is set from. the push rod.

29. 'An adjuster to maintaina normal travel of the piston contained in an air brake cylinder, comprising a rotatable member provided with a plurality of circumierentially arranged elongated ratchet teeth, a member comprised in the brake rigging and operatively connected with the rotatable member, a push rod of the brake equipment, means for operating the rotatable member upon abnormal movement of said push rod, said means including a pawl carried by an operating arm and engageable with said ratchet teeth, said rotating member having a second series of relativelysmall teeth extending therearound and arranged in succession one immediately adjacent to the other, said teeth being equidistantly spaced and with a plurality of said teeth within the perpendicular alignments of said first series of teeth, a pawl engaging said second series of teeth for holding the rotatable member against retrograde movement, said second pawl and said second series of teeth being adapted to cooperate with said first pawl and the first series of teeth whereby the said second pawl successively engages several of the teeth of said second series between the actions of said first pawl engaging successively two adjacent teeth of said first series, means for supporting the aforesaid parts and members and controlling their movements, the operation and combinations of the above parts and members substantially as disclosed and specified.

30. An adjuster to maintain a normal travel of the piston contained in an air brake cylinder, comprising a rotatable member provided with a plurality of circumferentially arranged elongated ratchetteeth, a member comprised in the brake rigging and operatively connected with the rotatable member, a push rod of the brake equipment,

means for operating the rotatable member upon abnormal movement of said push rod, said means including a pawl carried by an operating arm and engageable with said ratchet teeth, said. rotatable member having a second series of relatively small teeth extending therearound and arranged in succession one immediately adjacent to the other, said teeth being equidistantly'spaced and with a plurality of said teeth within the perpendicular alignments of said first series of teeth, a pawl engaging a number of said second series of teeth for holding the rotatable member against retrograde movement, said second pawl and said second series of teeth being adapted to cooperate with said first pawl and said first series of teeth whereby said second pawl successively engages several of the teeth of the second series between the actions of said first pawl engaging successively two adjacent teeth of said first series, means for supporting the aforesaid parts and members and controlling their movements, the operation, structure and combinations of the above parts and members substantially as disclosed and specified.

31. In a brake equipment, the combination with a push rod, an operating mechanism, means for imposing movement upon said mechanism upon abnormal travel of the aforesaid rod, a lever interposed in and operatively connected with the rigging of the said equipment, means for holding said lever for swinging movement, a second lever interposed in and operatively connected with said rigging, means for holding the second lever for swinging movement, an operative connection between the aforesaid levers, means for imposing the said movement imposed upon said mechanism upon the aforesaid levers whereby slack is taken out of the aforesaid rigging and a substantially uniform brake piston travel is maintained, and means acting to maintain the aforesaid levers in proper position and to overcome the inertia thereof while the brakes are being released.

32. In a brake equipment, the combination with a push rod, an operating mechanism, means for imposing movement upon said mechanism upon abnormal travel of said rod, a lever interposed in and operatively connected with the brake rigging of the aforesaid equipment, means for holding said lever for swinging movement, means for imposing the movementof said mechanism upon the aforesaid lever, a second lever interposed in and operatively connected with said rigging, means for holding said second lever for swinging movement, an operative connection between said levers, the aforesaid movement imposed by said mechanism upon the first named lever eifecting the movement of the second named lever, the movements of said levers taking the slack out of the brake rigging and maintaining a substantially uniform brake piston travel.

33. A mechanism to control the travel of the piston contained in an air brake cylinder, comprising a rotatable member provided with a plurality of circumferentially arranged elongated ratchet teeth, a member comprised in the brake rigging and operatively connected with the rotatable member, a push rod of the brake equipment, an operating arm connecting said push rod with the rotatable member, a pawl carried by the arm and engageable with the ratchet teeth, said rotatable member having a second series of teeth extending therearound and arranged in succession one immediately adjacent to the other, said teeth being equidistantly spaced and with a plurality of said teeth within the perpendicular alignments of the first named teeth, a pawl engaging said second teeth for holding the rotatable member against retrograde movement, the first named pawl normally coacting with a single tooth 0f the first named series but engaging an adjacent tooth following'the action of the second named pawl engaging a succeeding number of the second series of teeth upon abnormal travel of the push rod, the said second pawl and the second series of teeth being adapted to cooperate with the first named pawl and the first series of teeth whereby the said second pawl successively engages several of the teeth of the said second series between the actions of the first named pawl engaging successively two adjacent teeth of the first named series, with a definite number of teeth in each of the aforesaid series, said mechanism being adapted to determine the travel of the piston by the distance said rotatable member is set from the push rod, the combination hereinabove set forth being adapted to operate simultaneously with the brake application, and thereby effecting a resistance to undesired action substantially as specified.

34. A mechanism to control the travel of the piston contained in an air brake cylinder, comprising a rotatable member provided with a plurality or" circumferentially arranged elongated ratchet teeth, a member comprised in the brake rigging and operatively connected with the rotatable member, a push rod of the brake equipment, an operating arm connecting said push around and arranged in succession one immediately adjacent to the other, a pawl engaging her against retrograde movement,

said second teeth for holding the rotatable member against retrograde movement, the first named pawl normally coacting with a single tooth of the first named series but engaging an adjacent tooth following the action of the second named pawl engaging a succeeding number of the second series of teeth upon abnormal travel of the push rod, with a definite number of teeth in each of the aforesaid series, said mechanism being adapted to determine the travel of the piston by the distance said rotatable member is set from the push rod, the combina tion hereinabove set forth being adapted to operate simultaneously with the brake application and thereby effecting a resistance toundesired action substantially as specified.

35. An adjuster to maintain a normal travel of the piston contained in an air brake cylinder, comprising a rotatable member provided with a plurality of circumferentially arranged ratchet teeth, a'member comprised in the brake rigging and operatively connected with the rotatable member, a push rod of the brake equipment, means for operating the rotatable member upon abnormal travel of the push rod, said means including a pawl carried by an operating lever and engageable with the ratchet teeth, said rotatable member having a second series of teeth extending therearound, a pawl engaging the said second teeth for holding the rotatable memthe first named pawl normally coacting with a single tooth of the first named series but engaging an adjacent tooth following the action of the second named pawl, engaging a succeeding number of the second series of teeth upon abnormal travel of the push rod, the combination hereinabove set forth being adapted tooperate simultaneously with the brake application and thereby effecting a resistance to undesired action sub-' stantially as specified.

36. In combination with the elements of a brake rigging and a push rod, a slack adjuster for said rigging, said slack adjuster including an operating mechanism, a lever operatively connecting said push rod with said operating mechanism, means carried by said lever to actuate said operating mechanism upon abnormal travel of said push rod, and a single transmission between said operating mechanism and an element in the central portion of said rigging, said transmission including a lever provided at its mid-portion with an operative connection with said element of said rigging substantially in the central portion thereof, said recited elements of the slack adjuster constituting means to take up slack in said rigging simultaneously with the brake application and thereby to effect a resistance to undesired action substantially as described. l i

3'7. In combination with the elements of a brake rigging, said elements including a live cylinder lever, a dead lever and an operative connection'between said levers, a brake cylinder, a push rod, a slack adjuster for said rigging, said slack adjuster including an operating mechanism, a lever operatively connecting said push rod with said operating mechanism, means carried by saidconnecting lever to actuate said operating mechanism upon abnormal travel of said push rod, and a single transmission between said operating mechanism and said dead lever, said transmission including a lever provided at its mid-portion with an operative connection with said dead lever in proximity to said brake cylinder, said recited elements of the slack adjuster constituting means to take up slack in said rigging simultaneously with the application of the brakes and thereby to eiiect a resistance to undesired action substantially as described,

38. In combination with the brake cylinder and push rod of a brake equipment and the elements of a brake rigging, said brake rigging being adapted to be operated by said push rod, a slack adjuster for said rigging, said slack adjuster including an operating mechanism, means operatively connecting said push rod with said operating mechanism, means operatively associated with said connectingflmeans to actuate said operating mechanism upon abnormal travel of said push rod, and an operative connection between said operating mechanism and an element comprised insaid rigging, said operative connection including a transmission lever provided at its mid-portion with an operativeconnection with said element of said rigging in proximity to said brake cylinder, said recited elementsof the slack adjuster constituting means to take up slack in said rigging simultaneously with the brake application and thereby to effect a resistance to undesired action substantially as described.

39. In combination with the brake cylinder and push rod of a brake equipment and the elementsof a brake rigging, said brake rigging being adapted to be operated by said push rod,

a slack adjuster for said rigging, said slack adsaid operating mechanism and an element in the central portion of said rigging, and operative connections from said last named element to both. ends of said brake rigging, said recited elements of the slack adjuster constituting means to take up slack in said rigging simultaneously with the brake application and thereby to effect a resistance to undesiredlaction substantially as described.

- JAMES W. CLARK. 

